Search results for "Distributed"
showing 10 items of 1260 documents
A Comparison Study of Modern Heuristics for Solving the Partitioning Problem in Distributed Virtual Environment Systems
2003
Fast Internet connections and the widespread use of high performance graphic cards are making Distributed Virtual Environment (DVE) systems very common nowadays. However, there are several key issues in these systems that should still be improved in order to design a scalable and cost-effective system. One of these key issues is the partitioning problem. This problem consists of efficiently assigning clients (3-D avatars) to the servers in the system. In this paper, we present a comparison study of different modern heuristics for solving the partitioning problem in DVE systems, as an alternative to the ad-hoc heuristic proposed in the literature. Performance evaluation results show that som…
A novel traffic splitting policy for performance improvement in wireless mesh networks
2009
Wireless mesh networks are expected to play an important role in the next-generation wireless communication systems as it can provide wide coverage and scalable broadband Internet access services. However, as more traffic is injected into the network it may lead to throughput degradation, packet loss and longer transmission delay. In this paper, we argue that network performance can be improved by cross-layer design over multiple layers and load balancing based on service types. Correspondingly, a novel traffic splitting policy which can potentially utilize diverse paths for transmitting traffic flows of different service types from the same router has been proposed and investigated. Such a…
Nonlinear beam self-cleaning in a coupled cavity composite laser based on multimode fiber
2017
International audience; We study a coupled cavity laser configuration where a passively Q-switched Nd:YAG microchip laser is combined with an extended cavity, including a doped multimode fiber. For appropriate coupling levels with the extended cavity, we observed that beam self-cleaning was induced in the multimode fiber thanks to nonlinear modal coupling, leading to a quasi-single mode laser output. In the regime of beam self-cleaning, laser pulse duration was reduced from 525 to 225 ps. We also observed a Q-switched mode-locked operation, where spatial self-cleaning was accompanied by far-detuned nonlinear frequency conversion in the active multimode fiber.
A gearbox model for processing large volumes of data by using pipeline systems encapsulated into virtual containers
2020
Software pipelines enable organizations to chain applications for adding value to contents (e.g., confidentially, reliability, and integrity) before either sharing them with partners or sending them to the cloud. However, the pipeline components add overhead when processing large volumes of data, which can become critical in real-world scenarios. This paper presents a gearbox model for processing large volumes of data by using pipeline systems encapsulated into virtual containers. In this model, the gears represent applications, whereas gearboxes represent software pipelines. This model was implemented as a collaborative system that automatically performs Gear up (by using parallel patterns…
Vendor lock-in problem in cloud storage
2015
Pilvitallennuspalvelut tuovat datan tallentamiseen ennennäkemättömiä etuja ja niiden hyödyntäminen on, sekä yksittäisillä kuluttajilla, että yrityksillä, yleistymässä. Teknologiassa on kuitenkin vielä ongelmia ilman ratkaisua. Turvallisuus-, sekä yksityisyysseikat ovat tunnetuimpia, ja niitä on tutkittu laajalti. Vähemmälle huomiolle on jäänyt, kuinka vaikeaa on palveluntarjoajan vaihtaminen. Palveluntarjoajan vaihtaminen aiheuttaa aina kustannuksia asiakkaalle. Tilannetta, jossa vaihtokustannukset ovat niin suuret, että ne estävät palveluntarjoajan vaihtamisen, kuvataan termillä "vendor lock-in" (toimittajaloukku). Tämän kandidaatintutkielman tavoitteena on kirjallisuuskatsauksen perusteel…
The Personal Repertoire and Its Materiality : Resources, Means and Modalities of Languaging
2023
The chapter is a theoretical discussion of the concept of personal repertoire and its application in the context of applied linguistics, particularly in the study of language learning and development. It questions conceptualisations that understand language learning as acquisition of abstract, decontextual and disembodied language knowledge and argues that learners’ know-how is not based on any kind of ‘mental grammar’, but on a personal repertoire of different multimodal semiotic resources. Bringing together ‘old’ and ‘new’ arguments for materialism, personal repertoires are examined focussing on how embodied agentive activity is intertwined with the socially structured environments and th…
Dynamics of brain activity underlying working memory for music in a naturalistic condition
2012
Working memory (WM) is at the core of any cognitive function as it is necessary for the integration of information over time. Despite WM’s critical role in high-level cognitive functions, its implementation in the neural tissue is poorly understood. Preliminary studies on auditory WM show differences between linguistic and musical memory, leading to the speculation of specific neural networks encoding memory for music. Moreover, in neuroscience WM has not been studied in naturalistic listening conditions but rather in artificial settings (e.g., n-back and Sternberg tasks). Western tonal music provides naturally occurring motivic repetition and variation, recognizable units serving as WM tri…
Multi-objective optimization for computation offloading in mobile-edge computing
2017
Mobile-edge cloud computing is a new cloud platform to provide pervasive and agile computation augmenting services for mobile devices (MDs) at anytime and anywhere by endowing ubiquitous radio access networks with computing capabilities. Although offloading computations to the cloud can reduce energy consumption at the MDs, it may also incur a larger execution delay. Usually the MDs have to pay cloud resource they used. In this paper, we utilize queuing theory to bring a thorough study on the energy consumption, execution delay and price cost of offloading process in a mobile-edge cloud system. Specifically, both wireless transmission and computing capabilities are explicitly and jointly co…
Col : A Data Collection Protocol for Vanet
2012
International audience; In this paper, we present a protocol to collect data within a vehicular ad hoc network (VANET). In spite of the intrinsic dynamic of such network, our protocol simultaneously offers three relevant properties: (1) It allows any vehicle to collect data beyond its direct neighborhood (i.e., vehicles within direct communication range) using vehicle-to-vehicle communications only (i.e., the infrastructure is not required); (2) It tolerates possible network partitions; (3) It works on demand and stops when the data collection is achieved. To the best of our knowledge, this is the first collect protocol having these three characteristics. All that is chiefly obtained thanks…
UAV-Assisted Data Collection in Wireless Sensor Networks: A Comprehensive Survey
2021
Wireless sensor networks (WSNs) are usually deployed to different areas of interest to sense phenomena, process sensed data, and take actions accordingly. The networks are integrated with many advanced technologies to be able to fulfill their tasks that is becoming more and more complicated. These networks tend to connect to multimedia networks and to process huge data over long distances. Due to the limited resources of static sensor nodes, WSNs need to cooperate with mobile robots such as unmanned ground vehicles (UGVs), or unmanned aerial vehicles (UAVs) in their developments. The mobile devices show their maneuverability, computational and energy-storage abilities to support WSNs in mul…